Aquatic dumbbell



FIG. 1 is a perspective view of an aquatic dumbbell, showing our new design;

FIG. 2 is a top plan view thereof, the bottom view being a mirror image;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof; and,

FIG. 6 is a rear elevational view thereof. 

The ornamental design for an aquatic dumbbell, as shown and described. 